Walter (Walther) Ruttmann (28 December 1887 — 15 July 1941) was a German film director and along with Hans Richter, Viking Eggeling and Oskar Fischinger was an early German practitioner of experimental film. Dadaist Hans Richter’s Rhythmus 21 was the first abstract film (1921) but „Lichtspiel Opus I“ of Walter Ruttmann was the first abstract animation to be screened publicly (1921).